As Bernie said, having two ways of doing the same thing, for example having both the RA and DHCPv6 determine the default gateway or on-link information, leads to both confusion and conflicts. Which one do you believe? If you're talking about security, both RA's and DHCPv6 can be spoofed - so adding redundant and conflicting information solves nothing.
Others can argue that either ND (RA's) or DHCPv6 can be abolished - but I would argue that separating concerns, like on-link/routing information from address acquisition actually gives you more freedom to design your network the way you want to in a very clean, and easily understandable way. For instance, you may choose to have two completely different approaches to doling out address information (in a central repository or DHCPv6 server, where you can easily control who gets to have access to the network), from routing/on-link information which is associated with the topology of the network and should be made consistent with the routing tables in the routers that manage that network. If the information is managed and accessable from two different sources, then it makes sense to have two different mechanisms for managing that information. If you have two different mechanisms, then they should be orthogonal and cleanly separate concerns to avoid conflicts and confusion. Just because "that's the way they did it in IPv4" is not a good reason to do it in IPv6 - we're supposed to be using the opportunity which is given to us by the total network upgrade to IPv6 in order to designing a better system than IPv4. - Wes Beebee -----Original Message----- From: Ralph Droms (rdroms) Sent: Saturday, August 11, 2007 6:29 AM To: Leino, Tammy Cc: ipv6@ietf.org; John Jason Brzozowski (JJMB) Subject: Re: prefix length determination for DHCPv6 This issue was discussed in the dhc and v6ops WGs at the last IETF meeting: http://www3.ietf.org/proceedings/07jul/slides/dhc-5.pdf - Ralph On Aug 10, 2007, at Aug 10, 2007,6:28 PM, Leino, Tammy wrote: > Thank you John. > > Has your working group considered adding this as a DHCPv6 option? > If the on-link router is not configured to transmit RAs, a DHCPv6 > option advertising the default gateway would be helpful in populating > the routing table. > > Best Regards, > Tammy > > > > -----Original Message----- > From: John Jason Brzozowski (JJMB) [mailto:[EMAIL PROTECTED] > Sent: Friday, August 10, 2007 6:20 PM > To: Hemant Singh (shemant); Leino, Tammy; ipv6@ietf.org > Subject: RE: prefix length determination for DHCPv6 > > > Hello Hemant, > > There is no DHCPv6 mechabism to explicitly transmit router/gateway > information. > > Regards, > > John > ###################### > John Jason Brzozowski, CISSP, RHCT > [EMAIL PROTECTED] > 484-994-6787 > ###################### > > -----Original Message----- > From: "Hemant Singh (shemant)" <[EMAIL PROTECTED]> > To: "Leino, Tammy" <[EMAIL PROTECTED]>; ipv6@ietf.org > Sent: 08/10/07 18:14 > Subject: RE: prefix length determination for DHCPv6 > > > ________________________________ > > From: Leino, Tammy [mailto:[EMAIL PROTECTED] > Sent: Friday, August 10, 2007 5:56 PM > To: ipv6@ietf.org > Subject: prefix length determination for DHCPv6 > > > > Hello, > > In implementing RFC 3315, I see no option or field in the IA_NA option > for a prefix length associated with an assigned IPv6 address. How > does the client determine the prefix length of the IPv6 address the > server is assigning? > > <hs> One way to to send a Prefix Information Option (PIO) for the > assigned address prefix in RA to the client. PIO includes prefix > length. > > </hs> > > Furthermore, in the absence of a configured IPv6 router on the link, > can the client use the DHCPv6 server to find a default gateway out of > the local network? > > <hs> I don't believe so. I'll let the DHCPv6 RFC authors like Ralph > Droms and Bernie Volz verify this one. > > </hs> > > Hemant > > If so, what RFC specifies this option? > > Any help or referrals to additional RFCs would be much appreciated. > > Best Regards, > Tammy Leino > > > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
